1. Field of the Invention
The present invention relates to a display device, and more particularly, to a lenticular type display device.
2. Discussion of the Related Art
Today, a two-dimensional display device is generally used. Recently, because of wideband communication networks, a three-dimensional display device has been researched and developed.
There are various types of three-dimensional image displays with various types, for example, a depth image type, a three-dimensional image type, a stereographic type and the like. The depth image type is used for three-dimensional computer graphics or an I-MAX movie. The three-dimensional image type is used for a holographic image. The depth image type and the three-dimensional image type require large amounts of data and result in a high cost. So, presently, the stereographic type is used widely.
The stereographic type display device displays a three-dimensional image using binocular parallax. When the right and left eyes look at respective two two-dimensional images, the two two-dimensional images are transferred to the brain and then the brain mixes the two two-dimensional images. Thus, three-dimensional images having depth and reality are perceived. The stereographic type display device includes a display device that uses specific glasses and a display device without glasses. The stereographic type display device without glasses is preferred to the stereographic type display device that uses the specific glasses because the stereographic type display device without glasses does not need the separate glasses. The stereoscopic display devices without glasses are divided into a parallax barrier type, a lenticular type, and the like. Of these types, the lenticular type has been mainly used.
FIG. 1 is a cross-sectional view illustrating a lenticular type display device according to the related art.
As shown in FIG. 1, the lenticular type display device includes a display cell 10 and a lenticular cell 20. The display cell 10 includes left-eye and right-eye red, green and blue pixels RL, RR, GL, GR, BL and BR. The left-eye red, green and blue pixels RL, GL and BL are for a left eye of a viewer 2, and the right-eye red, green and blue pixels RR, GR and BR are for a right eye of the viewer 2. The lenticular cell 20 includes a plurality of lens 22 arranged regularly. The lens 22 has a semi-cylindrical shape that extends along a direction perpendicular to a plane of FIG. 1. Two two-dimensional images for the left and right eyes are refracted and transferred to the left and right eyes, respectively, by the lens 22. Therefore, the viewer 2 perceives three-dimensional images due to the binocular parallax.
In FIG. 1, the lenticular type display device having a single view point is shown that the viewer 2 at one direction views the three-dimensional image.
FIG. 2 is a cross-sectional view illustrating a lenticular type display device having a multiple view point according to the related art.
As shown in FIG. 2, three viewers 4, 6 and 8 at different view points view a three-dimensional image through the lenticular type display device. To do this, a plurality of red, green and blue pixels R1, R2, R3, R4, G1, G2, G3, G4, B1, B2, B3 and B4 are arranged regularly. A right eye of the first viewer 4 corresponds to the first red, green and blue pixels R1, G1 and B1, and a left eye of the first viewer 4 corresponds to the second red, green and blue R2, G2 and B2. A right eye of the second viewer 6 corresponds to the third red, green and blue R3, G3 and B3, and a left eye of the second viewer 6 corresponds to the fourth red, green and blue R4, G4 and B4. A right eye of the third viewer 8 corresponds to the first red pixel R1, the first green pixel G1 and the first blue pixel B1, and a left eye of the third viewer 8 corresponds to the second red, green and blue pixels R2, G2 and B2. A lenticular cell refracts the two-dimensional images through the lens 22.
The related art lenticular type display devices have the following problems. The related art lenticular type display device is used only for a three-dimensional display device because the lens has permanent optical properties. If a viewer continues viewing a three-dimensional image for a long time using the lenticular type display device, the viewer feels tired. Accordingly, it is necessary that the three-dimensional image is changed into a two-dimensional image, however, it is difficult to change the image display modes in the related art lenticular type display device.
In the related art lenticular type display device, lenses having the same shape are used, irrespective of a refraction difference of red, green and blue colors. Accordingly, a chromatic aberration occurs.
FIG. 3 is a schematic view illustrating a chromatic aberration occurring in the related art lenticular type display device. In FIG. 3, for brevity of explanation, only red and violet light are shown.
As shown in FIG. 3, because red and violet light have different wavelengths but pass through the same lens, the red and violet light are focused at different points. This phenomenon is caused due to a chromatic difference of magnification. Therefore, display quality is reduced.